The present invention relates generally to apparatus and methods for nondestructive testing of electronic devices and, more particularly, to a novel method and apparatus for detecting leaks in glass-to-metal seals in microelectronic devices.
In the fabrication of certain microelectronic or hybrid electronic devices wherein sealing between metallic wires and glass feedthroughs and the body of the device is required, problems are presented in providing hermetic seals between the wires and the glass and between the glass and the body of the device. Suitable method and apparatus for quick and reliable determination, on a 100% quality control basis, of the integrity of the glass-to-metal seals of these devices is required by the manufacturers and/or users of these devices. Because the devices are often subjected to temperature excursions during use, a desirable method would include the detectability of leaks at elevated temperature.
The present invention meets the aforesaid need by providing a method and apparatus for detecting hermetic leaks in devices incorporating glass-to-metal seals, such as may characterize certain microelectronic and hybrid electronic devices. The invention utilizes a double-gasketed vacuum test station to isolate the glass-to-metal seals for exposure on one side of a heliumcontaining atmosphere and on the other side to an evacuated space monitored by a mass spectrometer helium leak detector to detect leaks through the seals. Controlled heating of the seals is accomplished by exposing the package containing the seals to radiant energy from an infrared lamp, and the seals may be leak tested under conditions of a preselected time/temperature control program.
It is, therefore, a principal object of the present invention to provide an apparatus for leak testing glass-to-metal seals under controlled heating conditions.
It is a further object to provide a quick and reliable method for leak checking glass-to-metal seals of certain electronic devices.
These and other objects of the present invention will become apparent as the detailed description of certain representative embodiments thereof proceeds.